Bug 850523 (part 1) - Add a "js-main-runtime-temporary-peak" memory reporter (2nd attempt).  r=wmccloskey,jlebar.

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extra : rebase_source : d90dcad2ed990b6e276ff38c36170b815ae9b823
Bug 850523 (part 2) - Use C++ comments in LifoAlloc.{cpp,h} (2nd attempt).  r=wmccloskey.

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extra : rebase_source : 6d96968f952086df7f4b7952a6926eb0f562bfde
Backout bc88f1602468, Bug 842911 - Remove support for Samsung mini-app mode r=blassey
Bug 848939 - De-field scale.xml. r=jaws
Bug 848939 - De-field videocontrols.xml. r=dao
Bug 848939 - De-field marquee. r=jaws